Improvement in safety-catches for elevators



F. B. PERKINS. Safety-Catches for Elevators. No. 162.252. Pa tented April20,1875.

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THE GRAPHIC C0.PNOTO,LITH.39 8:41 PARK PLAGE,N.Y.

FRANCIS B. PERKINS, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO WHITTIERMACHINE COMPANY, OF SAME PLACE.

IMPROVEMENT IN SAFETY-CATCHES FOR ELEVATORS.

Specification forming part of Letters Patent hlo. 162,252 dated April20, 1875; application filed March 27, 1875.

To all whom it may concern:

Be it known that I, FRANCIS B. PERKINS, of Boston, in the county ofSufi'olk and State of Massachusets, have invented an ImprovedSafety-Catch for Elevators, of which the following is a specification:

This invention relates to a device for looking the car or platform of anelevator or hoisting apparatus in its position in the event of thebreakage of one of the suspensories, and it consists it the combination,with the platform or car of a hoisting apparatus, of a lifting-bar, towhich the suspensories are applied, arranged so as to have no movementrelative to the car or platform while the suspensories remain intact,and so as to operate as alever upon breakage of one of the suspensories,and by such operation to cause pawls to engage ratchet-racks to lock thecar or platform in position, the weight of the car or platform and theload thereupon becoming the force operative to cause engagement of thepawls with the ratchet-rack upon breakage of one of the suspensories.

In the drawing, Figure 1 shows a side view of this mechanism as itappears when called into action by breakage of one of the suspensories.Fig. 2 is the opposite side view on a larger scale than seen in Fig. 1,exhibiting the parts as they appear with the suspensories intact and thecar hanging therefrom. Fig. 3 is a transverse sectional elevation of themechanism.

The platform or car, guide-posts, and guideratchet rack-bars a are ascommonly used. Instead of attaching the suspensories b b to the top orcross bar of a car or platform, they are connected to the ends of alifting-bar, c, which is shown as placed beneath the base d of the caror platform, and within loops 0, which restrain it from lateral motion,endwise motion being prevented by pins f, which pass through theguide-bar, and touch against the inner edges of the loops, in which theguidebar fits loosely, so that it may move up and down therein. Throughthe upper part of each loop passes a pin, g, said pins making bearingsfor the bar when the platform or car (I hangs suspended in its normalcondition, or making fulcrums or pivoting points or edges for thelifting-bar c to tip or incline upon when either suspensory breaks. h isa rocker-shaft mounted so as to move freely in bearings 45, and havingnear each end a rocker-arm, k, the free end of which passes looselythrough the lower end of a link, I, pivoted to the short arm of the pawl-lever m, hung on a pivot, n, secured to d. The pawl-cut or long arm ofeach lever m is made heavy enough to gravitate to the position seen inFig. 2, when not subjected to action through the lifting-bar c. Thearrangement shown in the drawings provides for two suspensories, whichare located closely along one side of the guiding-ratchet rackbars a.This might be supplemented by two other suspensories, similarly locatedon the other side of the guides at, and all the parts of the mechanismdescribed as novelties would then be duplicated, except the links 1 andlevers m, for the rocker-arms of the duplicated mechanism would thenpass through the lower ends of links I, and would work as and under thecircumstances herein described.

The operation is as follows: With the suspensories intact thelifting-bar 0 remains in position, as shown in Fig. 2, and the heavypawl-cut ends of levers m hang down, as seen in Fig. 2, clear of theedges of the ratchetteeth on a a as the car or platform is raised orlowered, but let either of the suspensories break, and then thelifting-bar 0 will pivot 011 one of the pins 9, and Will act as a lever,to the short arm of which the unbroken suspensory is attached, the longarm moving downward, striking one of the rocker-arms 7c, and moving theother through the connection of both with their shaft h, thus forcingboth the pawls into engagement with the ratchet-teeth. Should there bein duplicate lifting-bars, rocker-shafts, and rocker-arms, then abreakage of any of the suspensories would cause the pawls to engage theratchet-rack teeth and lock the car or platform, as before described.

The mechanism has been described as placed beneath the floor of the caror platform, as

there it will usually be located, because it is there most out of sight,and best shielded from accident; but when, for any reason, it cannotwell be so locatedas, for example, where a pit or opening cannot be madein the lower floor orl evel, which the platform or carfloor is toreach--it may be attached beneath the ceiling of a car, or to thecross-bar of a platform.

Two or more suspensories have never, in my experience, been known tobreak at the same time; still, to provide for a contingency so remote, aspring may be so placed as to operate to move the lifter-bar toward andagainst the rocker arms, should such breakage occur. Such a spring isshown in dotted lines over the lifter-bar in Fig. 2, arranged so as tomove the lifter-bar toward and upon the rocker-arms upon simultaneousbreakage of the suspensories.

I claim- In a hoisting apparatus having a suspended platform or car, thecombination of the liftingbar with the rocker-shaft, and its leversconnected to detaining-pawls, all adapted to operate, asset forth, withsuspensories, either intact or broken.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

FRANCIS B. PERKINS. Witnesses:

J. B. ORosBY, S. B. KIDDER.

